Exactly one year ago, the fashion icon signed with her modelling agency MiLK Management.
Holliday made history as the first model of her size (she's a UK 26) to ever sign with a major agency - a move that catapulted her to international fame.
Posting the above flashback snap on her Instagram, Holliday wrote "It's absolutely surreal to think this was a year ago today.
"I hadn't announced to the world yet that I signed with @milkmodelmanagement, and I had no idea how much it would change my life, and ultimately make history.
"2015 has been a whirlwind and I wouldn't have it any other way. Thank you for being part of my journey, the best is yet to come. Thanks for believing in me."
In honour of Holliday's anniversary watch the video above to learn 6 key facts about the model or scroll through the gallery below for some of her iconic photos: